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MFactory

MFactory Helical LSD for BMW E39 E46 E85 E86 E89 E81 E82 E87 E88 E90 E91 E92 E93 – Limited Slip Differential Upgrade (120d 123d 320d 325i 328i 330i 520d 525i 530i 535i Z4 2.2i 2.5i 3.0i)

MFactory Helical LSD for BMW E39 E46 E85 E86 E89 E81 E82 E87 E88 E90 E91 E92 E93 – Limited Slip Differential Upgrade (120d 123d 320d 325i 328i 330i 520d 525i 530i 535i Z4 2.2i 2.5i 3.0i)

£1,184.34
£1,259.94 £1,184.34
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Heads-up on cancellations & returns: if you cancel an order or return an item, you won't get back 100% of what you paid. We apply a 10% restocking fee, the outbound shipping is non-refundable, and we have to pass on Shopify / PayPal payment processing fees; these aren't returned to us when we refund you. International orders also lose on exchange-rate spread in both directions. If the original packaging is damaged or missing, a reboxing charge applies. For international orders specifically, if you refuse to pay our shipping invoice or supply a prepaid label after placing the order, the same deductions apply. We're upfront about this — please be sure of your purchase before ordering.

Torque-biasing differential upgrade for BMW E39, E46, E85, E86, E89, E81, E82, E87, E88, E90, E91, E92, E93

Transform the way your BMW drives with a helical gear ATB diff that puts usable power to both rear wheels. This Torsen-style unit dramatically improves traction off the line, sharpens corner exit drive and gives you confident acceleration in the wet and dry. Quiet operation, smooth engagement and rock-solid reliability make it a superb road, fast-road and circuit solution for diesel and petrol models alike.

If you are replacing an open rear end, chasing quicker lap times or simply want more grip without the compromises of a clutch-pack unit, this helical gear centre is the go-to drivetrain upgrade. It delivers consistent torque transfer without chatter and works brilliantly for daily use, spirited B-road driving, drag strip launches and track days.

What you will feel

  • Far better traction out of slow and medium-speed bends with reduced inside wheel spin
  • Stronger, more predictable drive in poor weather and on uneven surfaces
  • Smooth power delivery with no plates to grab or wear out
  • Stable turn-in and steering feel maintained under throttle
  • No special friction modifiers required, simple service routine

Engineering that lasts

  • Manufactured from premium Japanese SAE 4320 and SAE 9310 steels
  • Forged, double tempered and super sub-zero treated for exceptional toughness
  • Advanced shot peening for increased surface hardness and fatigue resistance
  • Optimised gear geometry for efficient torque bias and maximum grip utilisation
  • Built to handle high shock loads common in competition and hard launches
  • High quality Brighton-Best hardware throughout
  • Helical gearset design means no clutch packs, no routine rebuilds
  • Optional Race Pack upgrades available on selected platforms such as Honda and Mazda

Real-world feedback

We have installed and road-tested these helical diffs on multiple customer builds and the response has been excellent. Owners report faster corner exits, calmer traction control intervention and a big improvement in confidence on damp roads. It is a fit-and-forget performance differential that works day in, day out.

Fitment summary

1 Series

  • E81, E82, E87, E88 120d and 123d, 2004 to 2013, manual and automatic, final drive ratio 3.07 or lower

3 Series

  • E46 325i, 328i, 330i, 1998 to 2006, manual and automatic, final drive ratio 3.07 or lower
  • E90, E91, E92, E93 320d, 2004 to 2013, manual and automatic, final drive ratio 3.07 or lower

5 Series

  • E39 520d, 525i, 530i, 535i, 1995 to 2003, manual transmission

Z Series

  • E85, E86, E89 Z4 2.2i, 2.5i, 3.0i, 2002 onwards, manual and automatic, final drive ratio 3.07 or lower

If you are unsure about your final drive ratio or compatibility, contact us and we will confirm before dispatch.

Pre-shipment compatibility check

We verify fitment before shipping. Please add your UK registration or the last 7 of your VIN at checkout so we can confirm the correct application for your axle.

Professional installation

We recommend fitting at MJ Modifications in Warwickshire for a turnkey supply and install service. Request a fitted quote and lead time by emailing info@mjmodifications.co.uk. We can supply, install and road test your differential for complete peace of mind.

Part number

MF-TRS-05E46

Manufacturer

MFactory

Warranty

Lifetime warranty

Image for illustration. Actual appearance may vary by application.

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